The invention relates to an oscillating form roller in the inking mechanism of a printing press, the form roller including a roller shaft that is rotatably supported in bearings on both sides and a roller casing which is held at the shaft by way of bearings so as to be rotatable and axially displaceable relative to the shaft, with stops to limit the axial movement of the roller casing being fastened to the shaft in a manner secured against rotation. By way of a distributor roller in contact with the roller casing, the latter can be driven into rotation and axially displaced.
Oscillating form rollers operating according to this principle have been known for a long time. As an example of a more recent development, reference is made to European Patent No. 143,240. This reference discloses a specific configuration of such an oscillating form roller, with the axial displacement of the roller casing being effected against springs. The stops are here disposed within the roller casing. This construction is relatively expensive, particularly because of the two springs and their stops. An even greater drawback is that high quality bearings must be employed there between the roller shaft and the roller casing because these bearings must permit not only the axial displacement of the casing relative to the shaft, but must also absorb differences in the rates of rotation between the roller shaft and the roller casing ranging from zero to the maximum number of revolutions of the roller casing. Thus, two bearing systems are provided in the interior of the form roller, namely a pin bearing system and a ball bearing system. However, both bearing systems are only difficultly accessible for maintenance, which is a further drawback of this prior art system.